Zip-Ties, band clamps, rubber bands, twine, and twist-ties, etc. are all helpful little devices that serve a worthy purpose – unless it’s to hold down a trigger on a portable machine tool!
The trigger on an air-motor typically has a spring tension that requires compression to activate. This means the default is OFF when the operator is not actively depressing the power switch. On long machining operations, the temptation is to tie off the switch letting the machine operate on its own.
This is an avoidable safety hazard. If something goes wrong or an accident should occur, it would be difficult to react in time to get the machine to halt operation safely. In the case of injury, tangled clothing or control lines, even a slight delay could result in extreme injuries or even death.
Sometime the perceived slow movement speed of a rotating machine tool belies it’s true torque and power. When control lines, support ropes or cables, or clothing become entangled, they wind tightly with incredible force beyond any chance of human resistance. This can all happen remarkably fast and underscores the innovative safety significance of a “zero pinch point” machining systems such as our new TRIMAX™ lathe.
There are situations (with machines that are configured with multiple air motor inputs) when the power trigger on each separate air motor must be tied down to relinquish control to an air valve on the common pneumatic line. This is a rare exception to the rule where tie downs are a necessity, but in this scenario, the same safety cautions apply to the common air valve which should never be tied down for safety.
The bottom line is that tie downs on triggers create serious operational hazards and must be not done – for safety’s sake.